routerCanReuse and routerOnReuse is not called whe

问题:

I am trying to figure out the OnReuse and CanReuse parts of Angular2's Router and I'm hitting a wall. I modeled my code after the docs here, but for some reason I can't get the methods to call when the route changes. Not sure what I'm doing wrong. Here's my code:

app.component.ts

import {Component, OnInit, NgZone, View} from 'angular2/core';
import {Location, RouteConfig, RouterLink, ROUTER_DIRECTIVES} from 'angular2/router';
import {ProductTable} from './product-table.component';
import {AddProduct} from './add-product.component';

@Component({
    selector: 'app'
})
@RouteConfig([
    { path: '/', name: 'ProductTable', component: ProductTable, useAsDefault: true },
    { path: '/add-product', name: 'AddProduct', component: AddProduct }
])
@View({
    templateUrl: __resourcePath + '/html/app.html',
    directives: [ROUTER_DIRECTIVES, RouterLink]
})
export class AppComponent {

    public __resourcePath = __resourcePath;

    constructor(public location: Location) {

    }

}

product-table.component.ts

import {Component, NgZone} from 'angular2/core';
import {CanReuse, OnReuse, ComponentInstruction} from 'angular2/router';
import {NgClass} from 'angular2/common';

@Component({
    selector: 'product-table',
    templateUrl: __resourcePath + '/html/product-list.html',
    directives: [NgClass]
})
export class ProductTable implements CanReuse, OnReuse {

    public storeProducts: Store_Product__c[] = [];
    public selectedStore: string;
    public selectedCategory: string;
    public errors: { [id: string]: string } = {};


    constructor(private zone: NgZone) {

    }

    routerCanReuse(next: ComponentInstruction, prev: ComponentInstruction) {
        console.log('routerCanReuse fired');
        return true;
    }

    routerOnReuse(next: ComponentInstruction, prev: ComponentInstruction) {
        console.log('Reusing!');
        console.log(next);
        this.selectedStore = next.params['selectedStore'];
        this.selectedCategory = next.params['selectedCategory'];
        this.storeProducts = next.params['storeProducts'];
    }
}

回答1:

I think the docs are not clear enough, or we just looked up a wrong doc.

Angular will not consider a component is resusable if router navigates to a component of different type. The following explanation is extracted from Angular's source

[router-outlet's reuse method is ]Called by the {@link Router} during recognition phase of a navigation. If the new child component has a different Type than the existing child component, this will resolve to false. You can't reuse an old component when the new component is of a different Type. Otherwise, this method delegates to the child component's routerCanReuse hook if it exists, or resolves to true if the hook is not present.

It is likely that you never navigate from ProductTable to ProductTable. So CanReuse hook is never called. But you can try reusing strategy in components like ProductDetail where you will navigate from one item's detail to the next item's detail.